Amitabh Bachchan promotes GST ahead of rollout. Watch video

The historic Central Hall on June 30 will have starry presence -- from Bollywood megastar Amitabh Bachchan to business leader Ratan Tata at the launch of India's most sweeping tax reform, GST or Goods and Services Tax. Government appointed Amitabh Bachchan to promote Goods and Services Tax (GST), earlier, the brand ambassador was Olympic-medal winning badminton player PV Sindhu.

The Central Board of Excise and Customs made the 74-year-old Bachchan brand ambassador for GST. Video featuring him has already been shot. "GST - An initiative to create a unified national market," the finance ministry said in a tweet, attaching the video.

In the video, Bachchan explains GST as an unifying force just like the three colours in the national flag. GST is an initiative to create "one nation, one tax, one market".

Government aims to simplify a series of taxes with the rollout of GST. It will end many taxes, regulations and border levies by subsuming an array of central and state levies including excise duty, service tax and VAT. It is being dubbed as the most significant economic reform since BJP government came to power in 2014 and is expected to add as much as 2 percentage points to the GDP growth rate.

A four-rate structure that exempts or imposes a low rate of tax 5 per cent on essential items and top rate of 28 per cent on cars and consumer durables has been finalised. The other slabs of tax are 12 and 18 per cent.